6 research outputs found
Scaling analysis of FLIC fermion actions
The Fat Link Irrelevant Clover (FLIC) fermion action is a variant of the
-improved Wilson action where the irrelevant operators are constructed
using smeared links. While the use of such smearing allows for the use of
highly improved definitions of the field strength tensor we show
that the standard 1-loop clover term with a mean field improved coefficient
is sufficient to remove the errors, avoiding the need for
non-perturbative tuning. This result enables efficient dynamical simulations in
QCD with the FLIC fermion action.Comment: 5 pages, 3 figure
Isolating the Roper Resonance in Lattice QCD
We present results for the first positive parity excited state of the
nucleon, namely, the Roper resonance (=1440 MeV) from a
variational analysis technique. The analysis is performed for pion masses as
low as 224 MeV in quenched QCD with the FLIC fermion action. A wide variety of
smeared-smeared correlation functions are used to construct correlation
matrices. This is done in order to find a suitable basis of operators for the
variational analysis such that eigenstates of the QCD Hamiltonian may be
isolated. A lower lying Roper state is observed that approaches the physical
Roper state.
To the best of our knowledge, the first time this state has been identified
at light quark masses using a variational approach.Comment: 7pp, 4 figures; minor typos corrected and one Ref. adde